Supersensitized photographic silver halide emulsion



United States Patent 3,527,641 SUPERSENSITIZED PHOTOGRAPHIC SILVER HALIDE EMULSION Yoshiuki Nakazawa and Masanao Hinata, Kanagawa, Japan, assignors to Fuji Shashin Film Kabushiki Kaisha, Ashigara-machi, Ashigara-Kamigun, Kanagawa, Japan N0 Drawing. Filed Oct. 24, 1066, Ser. No. 588,710 Claims priority, application Japan, Oct. 22, 1965,

0/64,437 Int. Cl. G03c 1/28 U.S. Cl. 96-104 4 Claims ABSTRACT OF THE DISCLOSURE A photographic composition comprising a silver halide emulsion sensitized with a combination of two dilferent cyanine dyes. The combination of two difierent sensitizing dyes results in an increase in the sensitization of the silver halide emulsion above that which can be obtained with either dye employed alone.

The present invention relates to a silver halide emulsion sensitized by sensitizing dyes and more particularly it relates to a photographic silver halide emulsion super-dyesensitized by the combination of two types of sensitizing dyes.

It has been well known in technique for the production of photographic silver halide emulsions that by the addition of a sensitizing dye to a silver halide emulsion, the light-sensitive wave length range of said silver halide emulsion is enlarged and the emulsion is sensitized optically. It has also been known that the extent of sensitization by a definite sensitizing dye is varied according to the kind of emulsion to be employed. Further, the extent of sensitization of a definite emulsion by a definite sensitizing dye can be varied by varying the conditions in the emulsion. For example, the extent of sensitization is increased by increasing the silver ion concentration or reducing the hydrogen ion concentration, or by a combination thereof. However, the thus sensitized emulsion has the fault that the preservability of it is generally low.

Therefore, an object of the present invention is to provide a photographic silver halide emulsion sensitized by sensitizing dyes, not accompanied by the above-mentioned drawback, and without the necessity of varying the conditions in the emulsion, e.g., the silver ion concentration and/or the hydrogen ion concentration.

Another object of the present invention is to increase the sensitivity of a photographic silver halide emulsion without the above-mentioned drawback and further without varying the conditions in said emulsion.

The inventors have found that by incorporation in a photographic silver halide emulsion the two types of sensitizing dyes, shown below, a higher sensitivity is obtained by the interaction of the two sensitizing dyes as compared with the case of using each sensitizing dye individually.

In accordance with the instant invention, the sensitivity of a photographic silver halide emulsion is increased by incorporating therein the halogen-substituted mesoethyl thiacarbocyanin having the following general Formula I,

3,527,641 Patented Sept. 8., 1970 and the sensitizing dye represented by the following general Formula II;

1'22 wherein W and W each represents a halogen atom; R and R each represents an alkyl group (such as a methyl group, an ethyl group, or a propyl group), a substituted alkyl group (such as a B-hydroxyethyl group, a B-acetoxyethyl group, a 'y-acetoxypropyl group, an ethylsulfate group, and a propylsulfate group), a carboxyalkyl group or a derivative thereof (such as a carboxymethyl group, a fi-carboxyethyl group, and a 2-(2-carboxyethoxy) ethyl group), a sulfoalkyl group or a derivative thereof (such as a fi-sulfoethyl group, a 'y-sulfopropyl group, a a-sulfobutyl group, a Z-hydroxy-l-sulfopropyl group, a 2-(3-sulfopropoxy)ethyl group, a Z-acetoxy-l-sulfopropyl group, a 2-(2-(3-sulfo-propoxy)ethoxy)ethyl group, and a 2-hydroxy-3-(3'-sulfopropoxy)propyl group), an allyl group, an aryl group, a substituted aryl group, or an aralkyl group; X represents an anion; and n is 1 or 2, said 11 being wherein R and R are same as R and R in Formula 1; R represents an alkyl group, such as a methyl group and an ethyl group; Y and Y each represents a sulfur atom or a selenium atom; V V V and V each represents a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxyl group, an aryl group or a halogen atom; R being a methyl group, if Y and Y are sulfur atoms, V and V are hydrogen atoms, and V and V, are halogen atoms; X represents an anion; and n is 1 or 2; said 11 being 1 when an inner salt is formed.

Since, in the case of sensitizing a photographic silver halide emulsion by the combination of the above two kinds of sensitizers, no conditions in the emulsion, such as the silver ion concentration and the hydrogen ion con centration, need be varied, we call the novel sensitization a super-dye sensitization.

That is, the photographic silver halide emulsion of the present invention contains therein at least one sensitizing dye represented by the above-mentioned general Formula I and at least one sensitizing dye represented by the abovementioned general Formula II.

As the emulsion to be employed in our invention there may be used the usual gelatino silver halide emulsions, but protective colloids other than gelatin, such as a resinous material or a cellulose derivative which have no bad influence on the photographic properties of the light sensitive element may also be used.

The sensitizing dyes of this invention may be used in various concentrations, but a particularly elTective proportion of sensitizing dye (I) or sensitizing dye (II) is from 0.02 to 0.4 g. per one gram molecule of the silver halide. The concentration ratio of dye (I) to dye (II) is preferably from 10:1 to 1:10.

The sensitizing dyes may be incorporated in the emulsion in a conventional manner. For example, they may be added therein as a solution thereof in an organic solvent, such as methanol or ethanol, or in water. It is convenient to add sensitizing dye (I) and sensitizing dye (H) to the silver halide emulsion before coating. Further, sensitizing dye (I) may be incorporated in the silver halide emulsion before or after the addition of dye (II), or a mixed solution of dye (I) and dye (II) may be added to the emulsion.

The silver halide emulsion to be used in the present invention may contain further usual additives, such as a. chemical sensitizer, an anti-foggant, a hardening agent, a wetting agent, a stabilizer, a developing promoter, an anti-bronzing agent, a coupler, a fluorescent whitening agent, and an air-fog preventing agent.

Further, since the photographic silver halide emulsion sensitized by the sensitizing dyes of this invention may be provided with highly sensitive color sensitivity, in compliance with the purpose, by increasing the green sensitivity with the addition of pseudocyanin, oxacarbocyanin, imidacarbocyanin or merocyanin, color sensitization for black and white light sensitive elements, using various silver halide emulsions, can be easily conducted.

Moreover, in the case of applying the present invention to a silver halide light sensitive emulsion for a red sensitive layer of a photographic light sensitive color element, by reducing the addition amount of sensitizing dye (II) as compared with that of sensitizing dye (I), the color sensitization for high red sensitivity can be conducted without increasing the green sensitivity so much. In this case, by suitably selecting the sensitizing dye from dye (I), a coupler may be incorporated in the emulsion together with the sensitizing dyes.

The silver halide emulsion sensitized by the sensitizing dyes of the present invention may be applied in a conventionally employed manner to a suitable support such as a glass plate, a film of cellulose derivative, a synthetic resin film or a paryta paper.

The present invention will be more fully understood by making reference to the following examples.

EXAMPLES 1-20 A gelatino silver iodo-bromide emulsion which had been prepared in a conventional manner was mixed with the following:

1) A sensitizing dye selected from the ones shown by general Formula I,

(2) A sensitizing dye selected from the ones shown by general Formula I and a sensitizing dye selected from the ones shown by general Formula II, or

(3) A sensitizing dye selected from the ones shown by general Formula II.

In the examples various silver halide emulsions were used, although in each set of examples the same emulsion was used. The sensitizing dyes employed will be described below. After the addition of the sensitizing dyes, the silver halide emulsion was allowed to stand for 30 minutes at 35 C. and then was applied to a film support.

The sensitivity of the thus coated light sensitive film was shown by the read sensitivity exposed through Fuji No. 7 Filter (transmitting light having a wave length longer than 590 m and made by Fuji Shashin Film Co.). The thus exposed film was developed in a developer having the following composition for 7 minutes at 20 C.;

Water to make 1 liter.

The results are shown in the following table. In the table, the sensitivity was shown by M.U.D. (a reciprocal of the amount of exposure necessary for giving the 4 density of fog plus 0.1, multiplied by 10). Further, the numerical value shown in the parentheses appearing after the name of sensitizing dye is the proportion of the sensitizing dye shown by the number of milli-liter of mol solution thereof per kg. of emulsion.

Example Red sen- No. Dye(s) and amount sitivity Fog 1 (a) 5, 5-dichloro-3, 3', Q-trIethylthia- 191 0. 09

carbocyanin bromide (2). (b) 3, 3-dlethyl-Q-methyl-selena- 56 0. 10

carboeyanin iodide (2). (c) Dye (a) (2) dye (b) 2 513 0.13 2 (d) 3, 3- diethyl-5, 5, 9triethy1selena- 70 O. 08

carboeyanin bromide ye (a) y (2) 550 0. 09 3 (f) 3, 3-di-B-hydroxethyl-6, 6, Q-tri- 50 0. 10

ethylthiacarbocyanin bromide (2). (g) Dye (a) (2) y (2) 500 0.13 4 (h) 3, 3-diethyl-6, 6,9-tr1methylthia- 72 0. 10

earbocyanin bromide (2). (i) Dye (a) (2) -I dye (h) (2) 427 0. 13 5 (j) 3, 3-di-fi-hydroxyethyl-Q-ethylthia- 200 0.08

earboeyanin (2). (k) Dye (a) (2) dye (1) (2) 480 0. 10 6 (1) 3, 3-di-B-hydroxethyl-Q-methyl- 35 0. 08

thiacarboxyanin (2). (m) Dye (a) (2) dye (1) (2) 457 0. 13 7 (n Dye (a) (6) 205 0.08 (o) 3, 3-dl-fl-hydroxyethyl-5, 5' ,6, 30 0. 08

ramethyl-9-ethyl-thiacarbocyauin bromide (2). (D) Dy y 398 09 8 (q) Dye 4 182 0. 07 (r) 5, 5-diethoxy-3, a, e, 6-tetras9 0. 11

methyl-Q-ethylearbocyanln thioeyanate (2). (s) Dye (a) (4) dye (r) (2) 479 0. 13 9 (t) 5, 5'-diethoxy-6,6'-d1methy1-3, 3'-9- 132 0.10

trrethylthiacarboeyanin bromide (2 (u) Dye (a) (4) dye (t) (2) 575 0. 12 10 (v) 3, 3-diethyl-Q-methylthiaearbm 78 0.07

cyanln bromide (2) (w) Dye (a) (4) dye (v) (2) 550 0. 07 11 (x) 3, 3-di-p-hydroxyethy1-5, 5-di- 151 0.10

ethoxy-6, 6-dimethyl'9-ethylthiacarboxyanln bromide (4). (y) Dye (a) (4) dye (x) (2).... 575 0. 07 12 (a) Anhydro-b,3di-y-sulfopropyl-5,5 191 0.07

dichloro-Q-ethylthlacarboeyanln hydroxide (6). (b) 3, 3-fl-hydroxyethyl-5, 5'-dlmethyl- 141 0. 07

Q-ethylthiacarboeyanin o i i i1 (d) (3) 312 o 09 c ye (a ye 13 (d) Dye d) 49 0.07 (e') Dye (e') (6) dye (d) (1.5) 355 0. 08 14 (t') Anyhdro-3,3-di-5-sulfobutyl- 282 0.07

5, 5-9-trimethylthiacarbocyanin hydrooxlde (2). (g') Dye (a) (2.5) dye (1') (2) 468 0. 07 15 (h) Anhydro-3,3'-di-6-suliobutyl- 174 0.06

5, 5-dichlorwQ-ethylthiacarb0- cyanln hydroxide (8). (1') Dye (d) (3) 71 0.06 (i) Dye (h) (8) dye (d) (3)- 380 0.07 16 (k) Anhydro-3,3'-B-carboxyethyl- 24 0.06

5 5, 6, 6-tetramethyl-9ethy1- thiacarboeyanin hydroxide (3). (l') Dye (h') (8) dye (k) (3) 324 0.06 17 (m' D e 85 0.06 (n) Dye (h) (8) dye (o) (3) 324 0.06 18 (0) Anhydro-3,-ethyl-3-'- -sulfo- 49 0.06

propy1-9-methylthiaselenaoarboeyanln (3). (p) Dye (h) (8) dye (0) (3) 363 0. 07 19 (q) Anhydro5, 5-diehloro-3 'y-su1i0- 0.07

propyl-S, Q-diethylthiaearbocyanin hydroxide (1.5). (r) Dye (d) (1.5). 51 0. 07 (s') Dye ((1') (1.5) dye (d) (1.5).. 363 0.07 20 (t) Anhydro-3,3-di-2"-(2-(3- 132 0.07

sulfopropoxy) ethyl-5, 5'-diehloro-Q-ethyl-thiaearboeyanin hydroxide (1.5). (u) Dye (t) (1.5) dye (d) (1.5) 347 0.07

In the above experiments, the silver hahde employed was as follows:

Examples 1-7 employed the same batch of a silver iodo-bromide emulsion (iodine 5.0 mol percent).

Examples 8-20 employed the same batch of a silver iodo-bromide emulsion (iodine 7.0 mol percent).

What is claimed is: 1. A photographic composition comprising: a sliver halide emulsion sensitized with a combination at least one sensitizing dye selected from the group consisting of those represented by the following general Formula I;

can

general Formula II;

Y Y r i C=OHO=CHO (X-).. 1

I'M I ls (II) Wherein R represents an alkyl group; R and R each represents a member selected from the group consisting of alkyl, hydroxyalkyl, alkoxyalkyl, sulfoxyalkyl, carboxyalkyl, (carboxyalkoxy) alkyl, sulfoalkyl, (hydroxy) sulfoalkyl, (alkoxy) sulfoalkyl, (sulfoalkoxy) alkyl, (hydroxy) (sulfoalkoxy) alkyl, (alkoxy) (sulfoalkoxy) alkyl, allyl, aryl and aralkyl; Y and Y' each represents a member selected from the group consisting of a sulfur atom and a selenium atom; V V V and V each represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxyl group, an aryl group and a halogen atom; said R being a methyl group when said V and V are hydrogen atoms, V and V; are halogen atoms, and Y and Y are sulfur atoms; X represents an anion; and n is 1 or 2, said It being 1 when an inner salt is formed. 2. The photographic composition as claimed in claim 1 wherein the proportion of said sensitizing dye represented by Formula I and said sensitizing dye represented by Formula II is from 0.02 to 0.5 g. per one gram molecule of the silver halide in said emulsion.

3. The photographic composition as claimed in claim 1 wherein the concentration ratio of the dye represented by Formula I to the dye represented by Formula II is from 1 to 1:10.

4. A photographic silver halide light sensitive element comprising:

a silver halide emulsion photographic layer sensitized with a combination of at least one sensitizing dye selected from the group consisting of those represented by the following general Formula I;

R2 (I) wherein W and W each represents a halogen atom; R and R each represents a member selected from the group consisting of alkyl, hydroxyalkyl, alkoxyalkyl, sulfoxyalkyl, carboxyalkyl, (carboxyalkoxy) alkyl, sulfoalkyl, (hydroxy) sulfoalkyl, (alkoxy) sulfoalkyl, (sulfoalkoxy) alkyl, (hydroxy) (sulfoalkoxy) alkyl, (alkoxy) (sulfoalkoxy) alkyl, allyl, aryl and aralkyl; X represents an anion; and n is 1 or 2, said It being 1 when an inner salt is formed, and

at least one sensitizing dye selected from the group consisting of those represented by the following general Formula II;

wherein R represents an alkyl group; R and R each represents a member selected from the group consisting of alkyl, hydroxyalkyl, alkoxyalkyl, sulfoxyalkyl, carboxyalkyl, (carboxyalkoxy) alkyl, sulfoalkyl, (hydroxy) sulfoalkyl, (alkoxy) sulfoalkyl, -(sulfoalkoxy) alkyl, (hydroxy) (sulfoalkoxy) alkyl, (alkoxy) (sulfoalkoxy) alkyl, allyl, aryl and aralkyl; Y and Y each represents a member selected from the group consisting of a sulfur atom and a selenium atom; V V V and V each represents a member selected from the group consisting of a hydrogen atom, an alkyl group, a hydroxyl group, an alkoxyl group, an aryl group and a halogen atom; said R being a methyl group when said V and V are hydrogen atoms, V and V; are halogen atoms, and Y and Y are sulfur atoms; X represents an anion; and n is l or 2, said 12 being 1 when an inner salt is formed.

References Cited UNITED STATES PATENTS 2,075,048 3/1937 Me s 96-104 2,206,076 7/1940 Carroll 96104 2,422,080 6/1947 Collins et al. 96-104 3,338,714 8/1967 Ficken et al. 96104 J. TRAVIS BROWN, Primary Examiner 

